Traditionally, mobile communication systems such as 3rd-generation (3G) mobile communication systems, LTE corresponding to 3.9-generation mobile communication systems, LTE-Advanced corresponding to 4th-generation mobile communication systems, and 5th-generation mobile communication systems are known. LTE stands for Long Term Evolution.
For example, regarding 5th-generation mobile communication systems, it has been considered that multiple types of OFDM-based communication in which symbol lengths (subcarrier spacings) are different are frequency-multiplexed (refer to, for example, the following Non-Patent Literature 1). OFDM stands for Orthogonal Frequency Division Multiplexing).
Examples of the related art include “Non-Patent Literature 1 [Technology & Standardization for 5G”, 3GPP RWS-150053, September, 2015]”.